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Ask Dr. Universe Agriculture
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What is the most poisonous thing in the world? – Macmillan, 16, India

Dear Macmillan,

There are some amazing deadly things out there. Like a frog that oozes poison from its skin. Or a jellyfish that uses itty bitty hooks to inject venom into its prey.

But it turns out the most poisonous thing on Earth is everywhere. It’s in our soil. It’s in our water. It might be in your kitchen.

It’s a species of bacteria called Clostridium botulinum.

I talked about it with my friend Susie Craig. She studies food safety at Washington State University.

She told me that C. botulinum makes the toxin that causes botulism. People can get it by eating … » More …

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Why in the world is the ice that polar bears depend on melting? — Maeve, 7, Canada

Dear Maeve,

There’s just something special about those powerful, snow-white polar bears. That’s probably why it’s so hard to learn about what’s happening to their habitat.

I talked about that with my friend Anthony Pagano. He used to work with the grizzlies at Washington State University’s Bear Center. He studies polar bears in Alaska.

He told me that scientists classify polar bears as marine mammals—like whales, dolphins and other mammals that live in the ocean.

“They’re reliant on the sea ice that occurs over the Arctic Ocean,” he said. “They use the ice as a platform to catch seals.”

Polar bears spend … » More …

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How is ice cream made? - Israel, 7

Dear Israel,

It just so happens that July is National Ice Cream Month. To celebrate, I decided to whip up some homemade ice cream. You can try it at home, too.

Put milk, sugar and vanilla into a freezer bag and seal it up tight. Fill another gallon freezer bag with ice and rock salt. Place the liquid mix bag inside the bag of ice and give it a good long shake. Some scientists might call this part "agitating." After five minutes or so, you'll notice the liquid mix in your bag becomes solid. Then you can dig in with a spoon.

After making my own homemade tuna-flavored ice cream, I decided to take a trip to the Washington State University Creamery to see how the professionals make ice cream for Ferdinand's Ice Cream Shoppe.

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Why do birds sing in the morning? – Alexandria, 9, Wisconsin

Dear Alexandria,

I usually write answers to kids’ science questions early in the morning. I like how it’s so quiet—except for my bird neighbors singing and singing.

I asked my friend Jennifer Phillips what’s going on. She’s a bird scientist at Washington State University.

She told me birds sing in the morning to tell other birds that their territory still belongs to them.

“The morning time is usually a little bit more calm, especially in windy areas,” Phillips said. “So, it's a good time to broadcast your song and for that song to potentially travel a little farther.”

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What safety measures can we take during extreme weather conditions? – Zadok, 8, Kenya

Dear Zadok,

When I was a kitten, a tornado tore through the neighborhood I was visiting. It got eerily quiet outside. Then the sky turned green. My littermates and I climbed into an empty bathtub to stay safe. After that, it got super loud.

I talked about extreme weather with Nathan Santo Domingo. He’s a weather scientist at Washington State University.

He told me that how to prepare depends on where you live. Different places have different kinds of extreme weather.

“Keep an eye on the forecast and know what's coming your way,” Santo Domingo said. “Be smart about what happens in your area.”

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Why are some veggies called fruits because of their seeds? – Valerie, 10, New Mexico

Dear Valerie,

Every summer I grow peppers in my garden. I always thought they were vegetables. But you’re right that my peppers have gobs of seeds like fruits do.

To figure out what’s going on, I talked with my friend Jacob Blauer. He’s a plant scientist at Washington State University.

He told me that whether something is a vegetable or fruit depends on what part of the plant it comes from.

“Plant products that come from plant parts like roots, leaves or stems are veggies,” Blauer said. “If they come from a flower and bear seeds, they’re a fruit in botanical and scientific terms.”

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How do plants that need very little water survive? – Alivia, 11, Maryland

Dear Alivia,

My neighbor has a very prickly garden. It’s full of cactuses—including one thorny plant nearly as tall as my house. That’s not something you see every day in the Pacific Northwest. Cactuses usually live in dry places like deserts.

I talked about your question with my friend Linda Chalker-Scott. She’s a garden scientist at Washington State University.

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What if there were no predators to eat the birds? – Katy, 10, Hawaii

Dear Katy,

Don’t let the lab coat fool you. I enjoy chattering at birds as much as the next cat. Staring out the window and vibrating my mouth to “chirp” helps me relax after a long day.

My wild cousins do take things a bit further—namely, predation. It’s not pretty, but it’s an important part of keeping life in balance.

I talked about predators with my friend Travis King. He’s a Ph.D. student at Washington State University. He studies big cats like lynx and jaguars.

“It's a balancing act between predators, disease, food and space,” King said. “If you take away predators, you lose one of the factors keeping an ecosystem in balance.”

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How do animals teach their kids how to survive if animals can't talk? — Riley, 11, Texas

Dear Riley,

There’s really nothing cuter than baby animals. Many animal parents invest lots of time into caring for their young and teaching them to survive.

I talked about your question with my friend Amber Adams-Progar. She’s an animal sciences professor at Washington State University. She’s also an expert in dairy cow behavior. She told me that non-human animals learn in ways that are like how humans learn.

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How do I make compost without a compost maker? – Miracle, 15, Nigeria

Hi Miracle,

My office is just down the road from the Washington State University composting facility. It processes more than 10,000 pounds of organic waste every month. That’s a lot of compost!

I talked about compost with my friend Jim Kropf. He works for WSU Extension. Extension programs connect universities with local communities. They offer classes and trustworthy, science-based resources that anyone can use online.

Kropf told me that composting is how nature recycles. “In the forest, leaves fall on the ground and come in contact with soil,” he said. “Worms, centipedes, microorganisms and fungi all work on those leaves to break them down into organic matter.”

Making compost is copying nature to make fertilizer for healthier gardens. It’s also a way to help our planet.

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Do animals feel home-like in wildlife sanctuaries? – Haniya, 8, Pakistan

Dear Haniya,

There are lots of things that make a place feel like home. Your home is probably full of sights, sounds and smells that feel familiar and cozy. Those things are important for animals in captivity, too.

To find out more, I talked with Charles Robbins, a wildlife biologist at Washington State University. He started the WSU Bear Center. It’s the only grizzly bear research center in the United States.

“The most important thing to bears and probably most animals is a feeling of safety—that they’re not being hurt, and the food is good,” Robbins said. “Probably all the same things that … » More …

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Dr. Universe: What’s the purpose of baking soda? What’s the purpose of baking powder? What’s the difference between the two? - Kyle, 9, Florida

When I got your question, I headed straight to my kitchen cabinet. I grabbed some baking soda and baking powder from the shelf and made some observations. Not only did the baking soda and baking powder look similar to one another but both contained an ingredient called sodium bicarbonate. Read More ...

Dr. Universe: How do tiny seeds make huge trees? – Robin, age 8

Dear Robin, If you’ve ever eaten a handful of trail mix, you’ve likely eaten quite a few seeds from trees. Some nuts, like cashews and almonds, are also seeds that can give us energy when we hike or play. Seeds actually store up their own energy in the form of something called starch, which is kind of like the food a seed needs to survive. The seed will use this stored up energy to start growing into a tree. Read More ...

Dr. Universe: Why do trees grow so slow? – Ana, 7, Covert, MI

When you eat food, you get a lot of important nutrients that help you grow. The trees that live on our planet also need some nutrients to grow. Trees use their leaves to help capture energy from the sun to make their own food. But as you may have noticed, a lot of trees lose their leaves during certain times of the year. Without leaves, they can’t make nearly as much food, and without those important nutrients, they can’t grow very fast. That’s what I found out from my friend Tim Kohlhauff, a certified arborist and urban horticulture coordinator at Washington State University. He is very curious about the lives of trees. Read More ...

Dr. Universe: How do worms help protect the dirt? -Fisher, 7, Palouse, WA

Dear Fisher,

Worms can help the soil in a few different ways. One helpful thing worms do is move around different materials, such as leaves and grasses, and make holes in the soil. That’s what I found out from my friend Lynne Carpenter-Boggs, a soil scientist at Washington State University, who was happy to help with your question. Lynne Carpenter-Boggs “Worms are actually very strong,” Carpenter-Boggs said. “They can break through soil and make holes that allow air, water and plant roots to follow those channels.” Read More ...

Dr. Universe: How do trees give us air to breathe? – Jamar, 11, Vineland, New Jersey

Our planet is home to all kinds of different plants, and they help make a lot of the oxygen we breathe. To find out how plants make oxygen, I asked my friend Balasaheb Sonawane. Sonawane is a scientist at Washington State University who researches photosynthesis, or the ways plants use energy from the sun and make oxygen. He said that in a way, plants breathe, too. “They don’t have a nose or mouth,” Sonawane said. “They have tiny microscopic organs on their leaves called stomata.” Read More ...

Dear Dr. Universe: Why do some cheeses stink? – Cody, 11

When you take a whiff of stinky cheese, that smell is coming from one of its very important ingredients: microorganisms. Microorganisms are so small, you’d need a microscope to see them, but sometimes they give off a big stink. To find out more about stinky cheese, I talked to my friend Minto Michael. Michael is a professor of dairy science at Washington State University and told me microorganisms do a few different jobs to help make cheese. Read More ...

Dr. Universe: Why do trees have sap? -Aliyah, 8, Kirkland, WA  

Just as blood moves important stuff around the human body, sugary sap moves important things around a tree. My friend Nadia Valverdi told me all about it. She’s a researcher at Washington State University who studies how apple and cherry trees survive in different environments. When we eat food, like a delicious apple or a handful of cherries, we get important nutrients. Read More ...

Dr. Universe: How do you make cider? -Julianna, 7

We can make cider with juice from apples. There are many different kinds of apples and a few different ways to squeeze out the juice. My friend Bri Valliere told me all about it. She’s a food scientist at Washington State University who knows a lot about cider. The first step is to pick out the apples. Honeycrisp apples will make a sweet cider. Granny Smiths are more acidic and will make a tart cider. “We could make a single batch of one kind, or we could mix different kinds of apples together and see how it turns out,” she said. “No matter what, it’s going to taste good.” Read More ...

Dr. Universe: Why do mushrooms grow in rings? We have a lot of giant ones in our yard right now! - Layne, 8, Spokane 

When you see a ring of mushrooms, it’s likely they are exploring for food under the ground. Giant mushrooms in your backyard are not animals or plants. They are part of another class of living organisms called fungi. But like you and me, they do need food to survive. That’s what I found out from my friend David Wheeler, an assistant professor at Washington State University, who knows a lot about fungi. He said the mushrooms are just one part of fungi. The other part that explores the soil for food actually lives under the soil. Read More ...

What is a tornado made of? - Alice, 6, Ames, Iowa

Dear Alice,

Have you ever felt a warm wind blow by you, followed by a cold gust of air? You can’t see it, but you can sense it on your skin. Invisible to you, winds mix together.

Usually, these winds are harmless. But under the right conditions, they can also be the main ingredients for a tornado.

To learn more, I chatted with Jon Contezac, Craig Oswald, and Joe Zagrodnik, a team of Washington State University scientists who are very curious about the weather.

To make a tornado, they explained, you need two big things: rising air and rotating air.

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Dr. Universe: What is inside a blade of grass and why is it green? Green is my favorite color. We really like reading your articles in our newspaper. – Luke, 5, Ogden, Utah

Dear Luke,

I’ve been wondering the same thing lately.  Every time I go on walks, I notice new splashes of color. Watching bugs in the grass, I pretend they’re crawling through a jungle. Everything is bright and bursting with green.

When I saw your question, I knew Michael Neff would know the answer. Green is his favorite color, too. (In fact, when we talked over video, he wore a green Hawaiian shirt.) Neff researches plants at Washington State University, and he is especially curious about grasses.

If you chopped a piece of grass and looked at it with your eyes alone, you might not see much. But if you looked at it under a microscope, you’d see tiny structures containing even tinier parts.

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Why are carrots orange? - Caden, 11, N.C.

Dear Caden,

When you picture the carrot section at a grocery store in the United States, you probably imagine rows of orange. But carrots can come in a rainbow of other colors: purple, yellow, red, and more.

And the first carrots weren’t orange at all. They were stark white.

That’s what I learned from Tim Waters, a Vegetable Specialist at Washington State University-Extension. He studies how to grow different kinds of vegetables, and helps others learn how to grow them too.

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Why do I like buffalo wings and not broccoli? - Joe, 10, New York City, NY

Dear Joe,

You’re not alone—cats don’t like broccoli much either. As a carnivore, I think a nice, meaty buffalo wing sounds great.

But humans are omnivores, meaning they eat both plants and meat. They’ve developed a taste for all kinds of things growing and living all over the world. So where do individual people’s preferences come from?

To find out, I visited Carolyn Ross, a professor of Food Science at Washington State University. Like you, she is very curious about why people like the foods they like.

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Dr. Universe: Do trees still create oxygen and clean the air after their leaves fall off? – Nova, 8, Palouse, Wash.

Dear Nova,

The trees that lose their leaves in fall, such as chestnuts, oaks, aspens, and maples, are called deciduous trees. Once they lose their leaves, most aren’t able to take in carbon dioxide gas from the air or produce any oxygen.

That’s what I found out from my friend Kevin Zobrist, a professor of forestry at Washington State University.

“Don’t fret, though,” Zobrist said. “For they more than make up for it in the summer.”

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Dr. Universe: How do trees help the air? – Ella, 12

Take a big, deep breath. As you inhale and exhale, you can probably feel the air taking up space in your lungs. The air we breathe is made up of a few different things. It includes gases such as nitrogen, oxygen, and carbon dioxide—just to name a few. Animals breathe in oxygen and breathe out carbon dioxide. But in the plant world, it’s the opposite. Trees, plants, and even algae in the ocean, take in carbon dioxide from the air and, using the energy of the sun, transform it into the oxygen we all breathe. Read More ...

Dr. Universe: What is the most smelliest fruit in the world? -Tiana, 9

Our world is full of fruits that have all kinds of delightful smells. Maybe you’ve smelled the sweetness of watermelon, pineapple, peach, papaya, or mango. But you might also be wondering about the most stinky fruit in the world. When I got your question, I asked my friend Lydia Tymon, a plant scientist at Washington State University. The first stinky fruit she thought of was the durian, a large, round fruit that grows mostly in Southeast Asia. The fruit is about a foot wide with a greenish-brown husk that has lots of spikes on the outside. Read More ...

Dear Dr. Universe: Why is the map the way it is? - Pablo, Spokane, Wash.

Dear Pablo,

Next time you eat an orange, try getting the peel off in one piece. Next, try to flatten out your peel. You’ll likely find it a bit tricky to make something round perfectly flat.

The same is true when we map our three-dimensional world onto a flat surface. It doesn’t work very well. That’s what I found out when I went to visit my friend Rick Rupp, a Washington State University researcher.

Rupp is an expert on geographic information systems, which can help us capture and analyze the geography of our planet. He explained that maps can show us all kinds of … » More …

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Why does meat get brown on the grill? – Christina, Seattle, Wash.

Dear Christina,

You know summer is just around the corner when the smell of barbecue is in the air. It’s a great question you ask and it leads us to the Meats Lab at Washington State University. That’s where I met up with my friend and animal scientist, Jan Busboom.

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What is the smallest insect on Earth? -Laurenz, 8, Molino, Philippines 

Dear Laurenz,

When I saw your question, I set out to explore with my bug net and a magnifying glass. I was searching all around for tiny insects when I ran into my friend Laura Lavine, a Washington State University scientist who studies bugs.

She said there are nearly a million different kinds of insects on Earth. The smallest of all the known ones are called fairyflies.

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Hi, Dr. Universe! When I was eating breakfast today, I came up with this question. Why does crispy rice make a popping sound when I pour milk over it? It makes me curious as a cat! -Allison, 11, Pullman, WA

Dear Allison,

My ears perked right up when I got your question. Like you, I’ve heard the sounds crispy rice cereal makes. But the truth is, I wasn’t entirely sure why it happens. There was only one way to find out.

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What is Dr. Universe's favorite experiment? -Garrett, 8th grade, Eastern Washington

Dear Garrett,

You know, your question reminds me of a couple other science questions from curious readers. Evangeline, age 7, wants to know why her hair is black. Sureya, age 8, wants to know why some people have curly hair.

It just so happens that one of my favorite science projects explores our questions about what makes us unique. It has to do with our DNA, or the blueprint for life.

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Why are ripe fruits sweet and why is it so important?  -Alexa, Schenzhen, China

Dear Alexa,

My friend Kate Evans said the answer really depends on whether you want the perspective of a person, a plant, or even a cat. Evans is a plant scientist at Washington State University in Wenatchee, where she investigates fruit in the Apple Capital of the World.

She explained how long ago, wild apples actually grew in forests. Without farmers around to plant them in orchards, trees had to scatter their own seeds to survive.

For some trees, the key to survival is growing sweet, ripe fruit.

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Will I ever like Brussels sprouts? - Susan 

Dear Susan,

Cats aren’t usually big veggie-eaters. But working with humans means that I get to taste all kinds of new delicacies—like Brussels sprouts.

I talked about food preferences with my friend Carolyn Ross. She’s a chemist and food scientist at Washington State University.

She told me that some people are extra sensitive to how foods taste. They’re called supertasters.

“Supertasters actually have more taste buds,” Ross said. “We’ve found that people who are supertasters are particularly sensitive to bitterness.”

Bitterness really strikes at a supertaster’s fungiform papillae. Those are the mushroom-shaped lumps on your tongue that house your taste buds. Because of … » More …

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